The book blurbs aren't raising novel points, and reviews of the book indicate that it doesn't do so either. It also takes one viewpoint in a field where intellectual opinion is diverse. It's questionable whether this is on-topic, but if you do want to inform discussions of altruism with relevant literatures, then I would advise linking to a representative sample of the existing work (which includes strong popular books like Sach's and Easterly's if you don't just want to link academic work) instead of the blurb for a single unrepresentative book that you haven't read.